ACP-TX-I and ACP-TX-II, two novel phospholipases A(2) isolated from trans-pecos copperhead agkistrodon contortrix pictigaster venom: biochemical and functional characterization

This work reports the purification and biochemical and functional characterization of ACP-TX-I and ACP-TX-II, two phospholipases A(2) (PLA(2)) from Agkistrodon contortrix pictigaster venom. Both PLA(2)s were highly purified by a single chromatographic step on a C-18 reverse phase HPLC column. Various peptide sequences from these two toxins showed similarity to those of other PLA(2) toxins from viperid snake venoms. ACP-TX-I belongs to the catalytically inactive K49 PLA(2) class, while ACP-TX-II is a D49 PLA(2), and is enzymatically active. ACP-TX-I PLA(2) is monomeric, which results in markedly diminished myotoxic and inflammatory activities when compared with dimeric K49 PLA(2)s, confirming the hypothesis that dimeric structure contributes heavily to the profound myotoxicity of the most active viperid K49 PLA(2)s. ACP-TX-II exhibits the main pharmacological actions reported for this protein family, including in vivo local myotoxicity, edema-forming activity, and in vitro cytotoxicity. ACP-TX-I PLA(2) is cytotoxic to A549 lung carcinoma cells, indicating that cytotoxicity to these tumor cells does not require enzymatic activity11CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ163536/2013-

Effect of mesoporous silica under Neisseria meningitidis transformation process: environmental effects under meningococci transformation

<p>Abstract</p> <p>Background</p> <p>This study aimed the use of mesoporous silica under the naturally transformable <it>Neisseria meningitidis</it>, an important pathogen implicated in the genetic horizontal transfer of DNA causing a escape of the principal vaccination measures worldwide by the capsular switching process. This study verified the effects of mesoporous silica under <it>N. meningitidis </it>transformation specifically under the capsular replacement.</p> <p>Methods</p> <p>we used three different mesoporous silica particles to verify their action in <it>N. meningitis </it>transformation frequency.</p> <p>Results</p> <p>we verified the increase in the capsular gene replacement of this bacterium with the three mesoporous silica nanoparticles.</p> <p>Conclusion</p> <p>the mesouporous silica particles were capable of increasing the capsule replacement frequency in <it>N. meningitidis</it>.</p

Effects of multi-walled carbon nanotubes (MWCNT) under <it>Neisseria meningitidis </it>transformation process

<p>Abstract</p> <p>Background</p> <p>This study aimed at verifying the action of multi-walled carbon nanotubes (MWCNT) under the naturally transformable <it>Neisseria meningitidis </it>against two different DNA obtained from isogenic mutants of this microorganism, an important pathogen implicated in the genetic horizontal transfer of DNA, causing the escape of the principal vaccination measured worldwide by the capsular switching process.</p> <p>Materials and methods</p> <p>The bacterium receptor strain C2135 was cultivated and had its mutant DNA donor M2 and M6, which received a receptor strain and MWCNT at three different concentrations. The inhibition effect of DNAse on the DNA in contact with nanoparticles was evaluated.</p> <p>Results</p> <p>The results indicated an in increase in the transformation capacity of <it>N. meninigtidis </it>in different concentrations of MWCNT when compared with negative control without nanotubes. A final analysis of the interaction between DNA and MWCNT was carried out using Raman Spectroscopy.</p> <p>Conclusion</p> <p>These increases in the transformation capacity mediated by MWCNT, in meningococci, indicate the interaction of these particles with the virulence acquisition of these bacteria, as well as with the increase in the vaccination escape process.</p

Advances in nanobiomaterials for oncology nanomedicine.

Nanobiomaterials in Cancer Therapy, discusses the most important findings in the field of cancer treatment. Novel therapeutic approaches utilize nanobiomaterials able to significantly enhance drug-loading capacity, formulation stability, and improve the efficiency of the drug. This book highlights the fabrication methods of platforms for multimodal and combinatorial therapeutic options along with simultaneous and real-time cancer imaging and innovative approaches for oncology by passive or active pathways of multifunctional nanocarriers. Engineered nanobiosystems for cancer therapy, prevention, low cancer recurrence, or relapse are also revealed and discussed. Volume VII contains 15 chapters, prepared by outstanding international researchers from the United States of America, Portugal, the United Kingdom, France, Mauritius, Romania, Russia, India, China, and Singapore. In Chapter 4, Advances in Nanobiomaterials for Oncology Nanomedicine, Patrıcia Severino et al. present an up-to-date review regarding nanobiostructures used for the development of innovative approaches for oncology by passive or active pathways

Chemical Modifications Of Phtx-i Myotoxin From Porthidium Hyoprora Snake Venom: Effects On Structural, Enzymatic, And Pharmacological Properties.

We recently described the isolation of a basic PLA2 (PhTX-I) from Porthidium hyoprora snake venom. This toxin exhibits high catalytic activity, induces in vivo myotoxicity, moderates footpad edema, and causes in vitro neuromuscular blockade. Here, we describe the chemical modifications of specific amino acid residues (His, Tyr, Lys, and Trp), performed in PhTX-I, to study their effects on the structural, enzymatic, and pharmacological properties of this myotoxin. After chemical treatment, a single His, 4 Tyr, 7 Lys, and one Trp residues were modified. The secondary structure of the protein remained unchanged as measured by circular dichroism; however other results indicated the critical role played by Lys and Tyr residues in myotoxic, neurotoxic activities and mainly in the cytotoxicity displayed by PhTX-I. His residue and therefore catalytic activity of PhTX-I are relevant for edematogenic, neurotoxic, and myotoxic effects, but not for its cytotoxic activity. This dissociation observed between enzymatic activity and some pharmacological effects suggests that other molecular regions distinct from the catalytic site may also play a role in the toxic activities exerted by this myotoxin. Our observations supported the hypothesis that both the catalytic sites as the hypothetical pharmacological sites are relevant to the pharmacological profile of PhTX-I.201310349

Draft whole-genome sequences of haemophilus influenzae biogroup aegyptius strains isolated from five brazilian purpuric fever cases and one conjunctivitis case

Brazilian purpuric fever is a febrile hemorrhagic pediatric disease caused by haemophilus influenzae biogroup aegyptius, a bacterium which was formerly associated with only self-limited purulent conjunctivitis. Here, we present draft genomes of strains from five Brazilian purpuric fever cases and one conjunctivitis case830FAPESP – Fundação de Amparo à Pesquisa Do Estado De São Paulo2011/01319-5; 2012/15046-

Silver nanoparticles obtained from Brazilian pepper extracts with synergistic anti-microbial effect: production, characterization, hydrogel formulation, cell viability, and in vitro efficacy

The synthesis of silver nanoparticles using plant extracts is known as a green approach, as it does not require the use of high pressure, energy, high temperature, or toxic chemicals. The approach makes use of plant extracts in a process called bioreduction, which is mediated by enzymes, proteins, amino acids, and metabolites found in bark, seed, and leaf extracts, transforming silver ions into metallic silver. This work aimed at developing silver nanoparticles (AgNPs) from Brazilian pepper, applying this green methodology. Hydroalcoholic extract of leaves of Schinus terebinthifolius Raddi was prepared and its concentration of polyphenols, tannins, and saponins quantified. The produced nanoparticles were characterized by UV-Vis spectroscopy, thermogravimetric analysis (TG), dynamic light scattering (DLS), and zeta potential (ZP). AgNPs were formulated in sodium alginate hydrogels to obtain a nano-based semi-solid formulation for skin application. The obtained silver nanoparticles of mean size between 350 and 450?nm showed no cytotoxicity against L929 mouse fibroblasts within the concentration range of 0.025?mg/mL and 10?mg/mL. Schinus terebinthifolius Raddi was found to enhance microbial inhibition against the tested strains, especially against gram-negative bacteria. Its potential use as an alternative to overcome bacterial resistance can be expected.This work was supported by the Banco do Nordeste do Brazil [FUNDECI/2016.0015], Conselho Nacional de Desenvolvimento Cientıfico e Tecnologico (CNPq), [443238/2014-6 and 470388/ 2014-5], Fundação de Apoio a Pesquisa e a Inovação Tecnológica do Estado de Sergipe (Fapitec), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), and the Fundação para a Ciencia e a Tecnologia (FCT/MCT) and from European Funds (PRODER/COMPETE) for the projects M-ERA-NET/0004/2015-PAIRED and UIDB/04469/2020 (strategic fund), co-financed by FEDER, under the Partnership Agreement PT2020.info:eu-repo/semantics/publishedVersio

Green Synthesis of a Novel Silver Nanoparticle Conjugated with Thelypteris glandulosolanosa (Raqui-Raqui): Preliminary Characterization and Anticancer Activity

In the last decade, the green synthesis of nanoparticles has had a prominent role in scientific research for industrial and biomedical applications. In this current study, silver nitrate (AgNO3) was reduced and stabilized with an aqueous extract of Thelypteris glandulosolanosa (Raqui-raqui), forming silver nanoparticles (AgNPs-RR). UV-vis spectrophotometry, dynamic light scattering (DLS), and scanning transmission electron microscopy (STEM) were utilized to analyze the structures of AgNPsRR. The results from this analysis showed a characteristic peak at 420 nm and a mean hydrodynamic size equal to 39.16 nm, while the STEM revealed a size distribution of 6.64–51.00 nm with an average diameter of 31.45 nm. Cellular cytotoxicity assays using MCF-7 (ATCC® HTB-22™, mammary gland breast), A549 (ATCC® CCL-185, lung epithelial carcinoma), and L929 (ATCC® CCL-1, subcutaneous connective tissue of Mus musculus) demonstrated over 42.70% of MCF-7, 59.24% of A549, and 8.80% of L929 cells had cell death after 48 h showing that this nanoparticle is more selective to disrupt neoplastic than non-cancerous cells and may be further developed into an effective strategy for breast and lung cancer treatment. These results demonstrate that the nanoparticle surfaces developed are complex, have lower contact angles, and have excellent scratch and wear resistance